@KiwiXC: we just shout to each other. Actually, it is pretty much one way communication. There is also a lot of the stoker following the movements of the captain, especially for popping jumps or soaking up bumps. Also, our Facebook is more frequently updated than the website. Search for jacksonrosetandem on Facebook

Or for more extreme corrections (like getting a long travel 29er into a decent pedaling position), run a riser bar upside down. And before anyone asks: No, it won't put your wrists at a weird angle, just rotate it to the right place the same as you would any other bar. It does look weird though.

While it's no XC bike, you can make 200mm climb a whole lot better than your average DH bike by using and appropriate suspension curve. It is also a little easier to make an efficient climbing tandem because there is less weight transfer between the wheels when you stomp on the pedals.
The 2.7" dual ply tires on the other hand, ouch!